Detection of Iberian ham aroma by a semiconductor multisensorial system

A semiconductor multisensorial system, based on tin oxide, to control the quality of dry-cured Iberian hams is described. Two types of ham (submitted to different drying temperatures) were selected. Good responses were obtained from the 12 elements forming the multisensor for different operating temperatures. Discrimination between the two types of ham was successfully realised through principal component analysis (PCA).     

Role of ghrelin in reproduction

Ghrelin, the endogenous ligand of GH secretagogue receptor type 1a, has emerged as a pleiotropic modulator of diverse biological functions, including energy homeostasis and, lately reproduction. Here, we review recent reports evaluating the reproductive effects and sites of action of ghrelin, with particular emphasis regarding its role as a molecule integrating reproductive function and energy status. Data gleaned from rodent studies clearly show that besides having direct gonadal effects, ghrelin may participate in the regulation of gonadotropin secretion and it may influence the timing of puberty. In addition, experimental data showing that ghrelin and/or its receptor are expressed in normal human ovary and testis as well as in human ovarian and testicular tumors raise the possibility that the ghrelin system may be involved in the control of cell proliferation in these tumors. We propose that ghrelin either acting as an endocrine and/or paracrine signal may play a major role in the endocrine network that integrates energy balance and reproduction.     

Differential hormonal regulation of estrogen receptors ERalpha and ERbeta and androgen receptor expression in rat efferent ductules

Estrogen receptors, in addition to the androgen receptor (AR), are expressed at high levels in efferent ductules of the male reproductive tract and it is now well recognized that estrogen receptor (ER) alpha is required for the maintenance of normal structure and function of the ductules. However, little is known regarding the hormonal regulation of the receptors themselves in the male. In the present study, efferent ductule ligation and castration, followed by replacement with testosterone, dihydro-testosterone (DHT) or estradiol was used to investigate the relative importance of circulating and luminal sources of steroid for the modulation of ERalpha, ERbeta and AR in rat efferent ductules. Uni- or bilateral castration and ligation did not affect the expression of ERalpha and ERbeta, but bilateral castration caused down-regulation of AR. Replacement with DHT and testosterone alone or in combination with estradiol caused the recovery of AR expression to control levels. A slight recovery of AR was also observed after estrogen replacement. ERalpha expression was decreased to nearly undetectable levels after estrogen replacement. On the other hand, ERbeta did not show evident effects following any of the treatments, suggesting a constitutive expression of this receptor. This differential modulation of the steroid hormone receptors highlights the importance of maintaining a physiological androgen-estrogen balance to regulate the structure and function of efferent ductules in the male.     

Prevalence of foodborne pathogens in grilled chicken from street vendors and retail outlets in Reynosa, Tamaulipas, Mexico

We analyzed a total of 70 grilled chicken samples bought randomly from street vendors and retail outlets in the city of Reynosa, Mexico, to determine the prevalence of Escherichia coli (Shiga toxin producing and enterotoxin producing), Salmonella spp., Staphylococcus aureus, Listeria spp., and Campylobacter spp. using microbiological methods and PCR detection of bacterial sequences. Of the 70 samples, 27 (38.5%) were from retail outlets and 43 (61.4%) from street vendors. All specimens were negative by both microbiological and molecular methods for Listeria monocytogenes, Shiga toxin 2 of Shiga toxin-producing E. coli, lt of enterotoxin-producing E. coli, and st enterotoxin, and all were negative for Salmonella spp. and Campylobacter jejuni by PCR. Of the samples studied, 49 (70%) had undetectable levels of the foodborne pathogens studied with the methods used. In the remaining 21 (30%) specimens, at least one pathogen was isolated or detected, with E. coli being the pathogen most frequently isolated and with two samples bearing the hlyA gene. We found no statistical difference in bacterial prevalence between retail and street vendor samples. The presence of pathogens in grilled chicken is an important public health risk because of the great demand for and daily consumption of this product in this region.     

Region-based current-source reconstruction for the inverse EEG problem

This paper presents a new method for the reconstruction of current sources for the electroencephalography (EEG) inverse problem, which produces reconstructed sources, which are confined to a few anatomical regions. The method is based on a partition of the gray matter into a set of regions, and in the construction of a simple linear model for the potential produced by feasible source configurations inside each one of these regions. The proposed method computes the solution in two stages: in the first one, a subset of active regions is found so that the combined potentials produced by sources inside them approximate the measured potential data. In the second stage, a detailed reconstruction of the current sources inside each active region is performed. Experimental results with synthetic data are presented, which show that the proposed scheme is fast, computationally efficient and robust to noise, producing results that are competitive with other published methods, especially when the current sources are effectively distributed in few anatomical regions. The proposed method is also validated with real data from an experiment with visual evoked potentials.     

高熔体流动速率茂金属聚丙烯性能评价

采用美国GRACE公司生产的茂金属聚丙烯（mPP）催化剂,在中国石油独山子石化公司国产第2代环管工艺聚丙烯装置上进行了高熔体流动速率mPP的生产,对产品性能进行了评价,并进行了熔喷布试生产。结果表明:生产的高熔体流动速率mPP熔体流动速率可达到150 g/min,其粉料经造粒后熔体流动速率下降约25%;与降解法熔喷料相比,高熔体流动速率mPP的结晶（熔融）温度、结晶度、灰分和挥发分质量分数明显较低,氧化诱导期相当,但混料后的高熔体流动速率mPP生产的熔喷布纤维较粗,布面偏硬,过滤效率低。     

实施线损精细化管理以提高节能效益的措施研究

首先介绍了线损的主要影响因素,进而分析了线损管理的精细化需求,最后从技术和管理2个角度分别提出了实施线损精细化管理以提高节能效益的措施。     

俄钢管冶金公司的新工艺新产品

阐述了近年来俄钢管冶金公司创新规划实施的主要成果。主要包括在生产连铸坯、焊管和无缝管、钢管精加工、镀层等方面的现有工艺的现代化和新项目的开发。     

不同排水板间距处理新吹填淤泥效果分析

采用浅表层技术对新吹填淤泥进行地基处理时,不同排水板间距对地基处理的效果必然不同。根据排水板间距的不同设置试验区,对试验区真空预压过程中的真空度、沉降、孔压进行监测。卸载时进行了钻孔取样和平板荷载试验,并计算了其固结度。     

Ca（OH）2的加入量对锆英砂碱熔分解过程的影响

在锆英砂与氢氧化钠质量比为1.0∶1.2时,分别选取锆英砂含量0.2%,0.4%,0.6%,0.8%和1.0%的Ca(OH)2作为添加剂,研究Ca(OH)2加入量对锆英砂碱熔分解过程的影响。采用X射线衍射仪和差热-热重分析仪对反应物料的组成和反应体系热量变化进行分析。结果表明:在Ca(OH)2加入量为1.0%时,锆英砂的分解率达到最大值,为96.4%,碱熔过程中在590℃以后发生剧烈的放热反应,锆英砂碱熔分解后的主要产物为Na2ZrO3和Na2SiO3。烧碱和添加剂复合分解锆英砂的适宜工艺条件为:烧结温度为750℃,烧结时间为30 min。